Siemens S7 300 ethernet

We are using siemens s7 300 cpu. For connection to other system ethernet connection and FC 5 was used. In the FC 5 data received said 108 byte but the data block for the receiving block 152 byte and only 84 bytes are used but other bytes are specified as spare.
My questions does this make it problem as received data to be 108 byte but in data block it is 152 bytes,where actual 84 bytes used others written as spare.

Thanks

Hello Arocon,

You shouldn't have any problem.

• The reception DB should be larger than the received data, as in your case.
• If you are receiving 108 bytes of data, but only using the first 84 bytes, that's no problem. You will get the 108 bytes sent by the other PLC.

Best regards,